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Full text of "The Cambridge Natural History"

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primary division, proposed to be called Paratheria, is that of the
Edentates. Probably the group so called should really be
divided into the Edentata and the EfTodientia, the latter con-
taining the Old "World forms. "Whether or not it be ultimately
shown that the Ganodonta are ancestral Edentates (sensu strictiorC),
the connexion of the group with others is not at present plain.
The same is the case with the extensive order of Rodents. It
is true that the extinct order of the Tillodontia shows certain
Rodent-like characters on the one hand, and likenesses to Ungulates
on the other. Certain likenesses shown by such apparently
diverse animals as the Rabbit and the Elephant used to be
insisted upon by Professor Huxley. For the present, however, the
Rodents must remain as an isolated group with only very
dubious affinities to others. The remaining groups of existing
mammals are easier to connect. At first the differences between
a Cat and a Horse seem to be quite as wide as those which
separate any two of the higher Eutherian orders. But it seems
to become clearer and clearer, as palaeontological investigation
proceeds, that the bulk of the Ungulate and the Carnivorous,
Insectivorous, and perhaps I^emuroid stocks converge into the
early Eocene Creodonta. From the Lemuroid branch the higher
Primates can be derived. The only " Ungulates " which cannot
be fitted in with some reasonable probability is the group of the
Proboscidea. But of the early forms of this division we have at
present no knowledge.